Tamping apparatus



Jan. 14, 1936,` N. D. LEVIN E1' A1.`

TAMPING APPARATUS Filed Jun zo, -1932 3 sheets-sheet 2 .fof

/NVENTo/Qs: N/LS D. LEV/N EBA/.5T E MULLEQ BYA, 777. ATTX "i 902 T l J. M, i936. N. D. LEvlN ET Al.

TAMPING- APPARATUS Filed Jun 2o, 1932 3 .Sheets-Sheet 5 /NvE-Nv'oes /V/Ls D, LEV/N i EEA/5T E MULLEB Y ATTN.

Patented Jan. 14, 1936 NETED STATES PATENT OFFICE TAMPING APPARATUS Application June 20, 1932, Serial No. 618,098

Claims.

Our invention relates to apparatus for injecting tamping material into a drill hole in a mine after a blasting charge has been placed in such hole, and effecting the tamping of such material in the drill hole, and one of the objects of our invention is the provision of improved and efficient apparatus adapted to be mounted on a truck travelling on a mine track and operable under the control of the operator by air pressure for introducing and tamping granular material such as stone dust or sand into a drill hole after a blasting charge has been placed therein.

Another object of our invention is the provision of an auxiliary chamber for receiving the tamping material from a hopper and combining with such auxiliary chamber controlling mechanism to enable air pressure to eiect a flow of the tamping material from such auxiliary chamber through delivery hose to a drill hole in advance of a blasting charge therein.

Another object of our inventionl is the provision of an improved and e'icient method of charging and tamping drill holes with granular material from a remote source of supply and securing uniformity of compactness of the tamping by regulating the air pressure.

Other objects of the invention will appear hereinaiter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings Fig. 1 is a plan View of truck mounted apparatus embodying our improvements;

Fig. 2 is an elevation of the truck mounted apparatus shown in Fig. l;

Fig. 2a is a detail view of the control valve between the compresser and the storage-tank;

Fig. 3 is a sectional elevation takenon the line 3 3 of Fig. 2 looking in the direction of the arrows;

Fig. 4 is an enlarged elevational view of the controlling mechanism for the compressor shown mounted on the truck in Figs. l and 2;

And Fig. 5 is an enlarged sectional elevation of ,the controlling mechanism for the compressor shown mounted on the truck in Figs. 1 and 2.

In Figs. 1 and 2 we have shown a truck frame 6 mounted on wheels l, l adapted to travel on a mine track 8. By means of a lever 9 pivoted at lil and connected through the link i l to the brake shoe l2 the truck frame may be retarded in its movement along the mine track or held on the latter ina stationary position. The lever 9 may be heldin brake applying position by the usual pawl and ratchet mechanism comprising the ratchet il.

(Cl. Sli-21) An electric motor VI3 mounted on the truck frame 6 is connected by means of the spur gears I4, I5 to an air compressor I5 which comprises an operating shaft I'I. This shaft extends loosely through a sheave I8 which may be connected to the shaft by means of a clutch I9 operable by means -of a lever pivoted at 2| and held in adjusted position by a latch 20 on an auxiliary lever 22 pivoted at 23.

When the power from the motor I3 is applied to the sheave I8 the endless rope 24 acts as a belt to transmit rotary movement to the sheave 25 on the cable reel 26. An electrically insulated cable 2l is connected to the electric motor I3, wound on the reel 26 and then extended through the winding guiding mechanism 28 to a distant source of electric supply. A driving sprocket 29 is mounted on the axis of the shaft I'I and is connected by the sprocket chain 30 to a driving sprocket 3l on the forward axle 32 of the wheel mounted truck. By means of a lever 33 pivoted at 34 and connected at 35 to a clutch 36 the latter may be applied to effect the transmission of power from the electric motor I3 to the sprocket chain 30 to effect propulsion of the entire machine along the mine track for transportation in the mine. The lever 33 may be held in either clutch releasing or clutch applying position by means of the latch 22', 33'.

The air compressor I6 is connected by a pipe 31 to a compressed air storage tank 38 which is mounted on the forward end of the truck G and secured thereto by the straps 39, 39, the ends of which are secured to the upper frame and the lower standards 4I. 'Ihe air pressure in the tank f 38 may be indicated by the pressure gauge 42,. The iow of compressed air from the compressor I6 through the pipe 31 `into the compressed air tank 38 may be controlled by means of the valve 43. When the lever 44 is in the horizontal position shown in Fig. 2 communication may be established between the compressor I6 and the tank 38 with the exhaust port 45 closed. When the lever i4 is moved to a vertical position extending below the pipe 31 the latter may be closed and the compressor I6 connected through the exhaust port 45 to the atmosphere. When the compressor I6 is connected to the atmosphere through the exhaust port 45 the electric motor I3 will be free to rotate either the sheave I8 when the clutch I3 f is applied or the sprocket 29 when the clutch 33 is applied; or both the sheave I8 and the sprocket 29 may be operated at the same time. If the air pressure in the storage tank is below normal, the

latter can, if desired, be lled up to normal pressure while travelling from one place to another, thus saving time.

After the truck with the apparatus mounted thereon as shown in Figs. 1 and 2 has been transported to a position near a coal face the brake l2 may be applied to hold the truck stationary on the mine track and the lever d@ moved to its horizontal position shown in Fig. 2. The electric motor I3 may then be operated while the clutches I9 and 35 are released. In order to secure automatic control of the pressure in the tank 38 the mechanism shown in Fig. 5 may be provided. rIhe structure here disclosed, and this structure in combination with the other elements of the device with which it co-operates, is disclosed and claimed in the co-pending application of Ernst F. Muller, Serial No. 699,131, which is assigned to The Jeffrey Manufacturing Company. The spur gear l5 is mounted in the casing 45 to rotate loosely around the shaft il. A cylindrical clutch element il extends from one side of the spur gear l5 and is provided on its inner cylindrical Y wall with a plurality of circumferentially spaced webs i8 which fit into slots of the clutch disks t9. The latter alternate with an additional set of clutch disks 5i), the inner edges of which are provided with 'slots fitting the circumferentially spaced webs 5l on the clutch element 52 which is keyed to the shaft il as indicated at 53.

Between the ring 55, which is secured to the spur gear l5 between the clutch elements 4'! and 52, and the circular thrust cap 55 the clutch disks 49 and 5B are arranged as shown in Fig. 5. The central portion of the circular thrust cap 55 is cylindrical and cup-shaped to t over the lefthand end of the shaft il. The outer cylindrical portion 55 of the cap 55 forms a cylindrical bearing for the ring 58 which is secured to the clutch element il? to effect an enclosure for the clutch disks.

A thrust pin 59 is secured to the operating arm 60 by means of the nut Si in position to engage the outer central portion 5I of the cap 55. An opening may be provided at S2 for the introduction of a lubricant to the shaft l1, thereby lubricating the contacting surfaces of the cap 55 and the shaft il. The opening S2 also permits free movement of the cap 55 relatively to the shaft il.

The upper end of the operating lever S9 is pivoted at 63 to the bracket @d which is secured to the casing cover d5. The lower end of the operating lever 6@ is provided with a fork 55 the lower ends of which are pivotally connected at 56 to a pair of horizontal links Si, 5'! the righthand ends of which (Fig. 5) are connected by a cross rod G8 slidable in longitudinal slots 69 in the rear portions of the walls of the cylinder It.

In the cylinder 'iii is an elongated piston 'il which is adapted to slide along the -cylinder 'i9 when air under suiicient pressure enters the chamber l2. The right end of the piston Il as shown in Fig. 5 engages the transverse rod 58 which extends transversely of the chamber I3. Inasmuch as the chamber I3 communicates with the atmosphere through the slots 59 the piston l! is free to slide along this chamber so far as air pressure therein is concerned.

Movement of the piston I! toward the left along the chamber "i2 is limited by the center pin 'H striking against the end wall i5 of the chamber l2. When the pin M engages the wall 'l5 the left-hand end of the piston I! will be adjacent the port 'F6 but will not close the same.

In the recess 1'! in the left-hand end of the shaft Il as viewed in Fig. 5 is a spring 18 which engages a cylindrical plug 'F9 bearing against the bottom of the central portion 5'! of thrust cap 55. When the air pressure in the chamber 'l2 is relieved so as to free the operating lever 50 the spring 18 will release the friction clutch 49, 59.

Mechanism is provided for operating the friction clutch automatically if sulcient pressure is available from the compressed air storage tank 38. The latter is connected by means of the pipe il? to the chamber 'l2 of the valve structure shown in Fig. 5. When the valve 95 is opened the compressed air passes through the port I6 into the chamber 'l2 and moves the piston li toward the right to cause the latter to exert pressure against the pin 68 to actuate the lever 60 in an anticlockwise direction. The thrust pin 5S will then exert a pressure against the central part of the thrust cap 5l which pressure is transmitted against the friction disks 49 and 5B. Since the friction disks i9 are revolving with the gear l5 the frictional resistance between the disks 49 and 5i! will causeY the compressor shaft Il to be rotated.

After the friction clutch shown in Fig. 5 has been applied to connect the motor i3 to the air compressor I6 connection will also be established between the motor i3 and the shaft l'! shown in Figs. 1 and 2. Therefore, whenever desired, the reel r26 may be rotated by operating the lever 20 to apply the clutch IS. Also when desired the shaft I1 may be connected to the truck propelling sprocket chain 35 by actuating the lever 33 to apply the clutch 38. The clutches I3 and 3E may be applied individually or simultaneously and held in applied or released positions by the latches 20 and 33. During transportation both clutches I9 and 35 are applied-to effect rotation of the reel 26 to pay out or wind up the cable 21 while at the same time the truck propelling mechanism is being operated. Furthermore, as above explained, if the air pressure in the storage tank 38 falls below normal as indicated by the pressure gauge 42 the valve M may be opened and the air compressor permitted to operate to restore the air pressure to normal in the storage tank 38, during transportation of the machine.

The automatic control of air pressure in the compressed air tank 38 may be understood by referring to Fig. 5 in connection with Fig. 1. V/'hen the valve 95 is opened and the pressure in the storage tank 33 is below a pre-determined amount the spring 8'! will push the piston 86 to the left to establish communication between the pipe il'l and the chamber 12 through the port '16. The pin 83 on the piston 8! then abuts against the cap screw 84. The iiow of the compressed air through the port 'i6 into the chamber 'l2 will push the piston 'H toward the right thereby applying the friction clutch as above described and consequently the air compressor is re-started. It should be noted that the lowest pre-determined pressure in the pressure tank 38 should be high enough to assure sufcient power to apply the friction clutch to effect starting of the compressor.

When a pre-determined maximum pressure in the pressure tank 33 has been reached any excess pressure will move the piston 8i to the right by overcoming the compression spring 3l, since the` left-hand side of the piston 3| in the cylinder 82 is in communication through the passageway 85 with the pipe Sl. It will thus be seen that when the desired maximum pressure in the pressure tank 3S has been reached the piston 8l will move toward the right as viewed in Fig. 5 and the port 16 will be closed. The pressure of the air confined in the chamber 12 will then diminish by leakage past the piston 1| which ts loosely in the cylinder 10. Consequently the pressure between the kdisks 49 and 50 of the friction clutch will be lessened to allow the disks to slip and the compressor shaft I1 to stop, preventing any further operation of the air compressor.

By permitting the valve 95 to remain open the operation of the air compressor including its starting and stopping will be entirely automatic so long as the electric motor I6 is operating.

Whenever the air pressure in the tank 38 falls so low that the friction clutch 49, 50 Vcannot be applied with sufcient pressure, starting operations may be effected manually by means of the lever` 89 which is pivoted at 90 and is provided with apressure arm 9| in position to'engage a cross-piece 92 of the operating lever B0. VBy starting the motor I3 and manually applying the friction clutch 49, 59 the air compressor I6 may be operated to supply pressure to the tank 38 while the valve lever 44 occupies its horizontal position shown in Fig. 2 with the passage-ways of the Valve 43 in the positions shown in Fig. 2a. After suiiicient pressure has been built up in the tank 38 the valve 8| will be automatically operated as above explained. It should be understood that the aircompressor I6 is connected to the tank 38 through the pipes 80, 31 and controlledby valve 43. The pressure in the tank 38 may be predetermined by the setting of the relief valve 95 in accordance with the reading on the pressure gauge 42 asshown in Fig. 2.

On the truck frame`V 6 between the air compressor I6 and the pressure tank 38 is mounted a large hopper 98 for containing the granular material such as stone dust or sand which is to serve as the tamping material.V At the bottom of thehopper 98 is an auxiliary circular chamber 99 formed by the hollow dome-shaped housing forming the partition which has a circular opening |0| in its upper side to receive the valve |02. The bottom of the chamber 99 is the upper ilat horizontal surface |03 of the upper side of the circularplate |04 which is secured rigidly to the dome-shaped housing |00.

The dome-shaped housing forming the partition |00 is provided with an annular flange |05 which is secured by means of cap screws |06 to the hopper floor plate |01 which is secured rigidly to the lateral longitudinal walls of the hopper 99. It will thus be seen that no communication is established between the hopper 98 and the auxiliary chamber 99 except through the opening |0| in the upper side of the dome |00 and this opening is controlled by the valve |02. A vertical rod |99 is rigidly connected at its lower end to the valve |02 and the upper end of the rod |08 is pivotally connected'at |09 to the lever |I0 shown in Figs. 1 and 3. The lever ||0 is fixed at III to the rockshaft ||2 which is journaled atits ends in the opposite side walls of the hopper 98. One end of the rockshaft I I2 is provided with an actuating lever ||3 as shown in Figs. 1 and 2.

The lever arm I0 .extends under the upper crosspiece ||4 which is connected between the upper edges of the opposite side walls of the hopper 99. The crcsspiece II4 serves as an abutment to prevent opening of the valve |02 by movement upwardly from the dome |00. By depressing the lever IIB the valve |02 may be opened by downward movement to its position illustrated in dotted lines at |02 in Fig. 3. The

98 into the auxiliary chamber 99 to fill the latter.

To facilitate the flow of the tamping material from the hopper 98 into the auxiliary chamber 99 a pipe II5 connects the pressure supply pipe 31 to the circular perforated pipe IIB. ferring to Fig. 3 it will be seen that the perforations ||1 in the circular pipe II6 are directed upwardly and angularly toward the valve opening 0| in the top of the housing |00. When the tamping material may then flow from the hopper By revalve 02 is Y'depressed to establish communication between the hopper 98 and the auxiliary chamber 99 the valve ||8 may be opened by the lever II9 as shown in Figs. 1 and 2. The air under pressure will then flow from the tank 38 through the perforations I I1 to aerate the tamp- After the chamber 99 has been iilled with the granular tamping material the Valve |02 is again Y closed by lifting the lever I|3 back to its initial position. The valve |02 preferably comprises an annular flexible element of leather, rubber or other flexible material which is held against a conical annular seat in the cone-shaped supportv |2| by means of the circular plate |22 and the lower screw threaded end |23 at the bottom of the rod |08.

The granular material that flows into the chamber 99 is forced by air pressure through the pipe |24 and the nozzle |25 for ow into the drill holes. The branch pipe |26 is connected between the air pressure supply pipe 31 and the annular chamber |21 which surrounds the depending annular skirt |28 as shown in Fig. 3. The lower edge of the annular skirt I 28 is spaced above the horizontal surface |03 of the bottom plate |04. Thelhousing |00, the skirt |28 and the peripheral support I 29 together with the annular flange |05 may be in one integral casting and the support |29 is so shaped as to make an air tight nt with the bottom plate |04.

The ow of the compressed air from the pipo 31 through the pipe |26 into the annular chamber |21 may be controlled by the valve |30 which is actuated by the lever I3I. A pipe |32 leads from the interior of the chamber 99 into the flexible hose |24.

It will thus be seen that by affording the relatively small auxiliary chamber 99 and closing the same by means of the valve |02 after the granular tamping material has illed this chamber a pre-determined pressure may be relied on to afford a uniform tamping of the granular material in the various drill holes into which it is directed by the opening of the valve |30 while the nozzle is inserted into the drill holes. When the valve is open, compressed air has free flow around the annular air space |21 and thence radially under the circular edge of the annular skirt |28. It should be understood that by reason oi the angle of repose of thegranular material in the chamber 99 such granular material will not ll the annular space |21. The annular distribution of the compressed air radially and inwardly7 under the edge ef the skirt will effect sufricient aeration of the granular material to produce a mixture of air and granular material to i effect free flow of the latter outwardly from the chamber 99 through the pipes 32 and flexible hose |24 and thence through the nozzle |25. The nozzle |25 may always be open because as soon as the Valve |30 is closed the flow through the from the nozzle.

hose |24 Will discontinue although still filled with the mixture of air and granular material. The auxiliary chamber 99 may be of sufficient capacity to afford operations to tamp a plurality of drill holes before it is necessary to re-open the valve |62 to re-ll the chamber 99.

The diameter of the nozzle E25 should be relatively smaller than the diameter of the drill hole so as to fit loosely in the latter and provide for escape of air from the drill hole during the tamping operation. Due to the expansion of the air while travelling through the hose and the nozzle the tamping material receives its acceleration and final velocity, when emerging The greater the final velocity of the tamping material the more effective will be the tamping action. Therefore, suicient clearance between the outer surface of the nozzle and the drill hole should be allowed to permit free escape of the air while the tamping material is lodged at the inner end of the drill hole.

As above explained this tamping operation may be regulated by having the pressure in the tank 38 uniform and confining the granular maly closed.

terial in the chamber 99 by the closure of the valve |92. When the air pressure is exerted in the chamber $9 the flexible element l2!) tends to expand radially to hold the opening l! tight- Therefore the only escape for the compressed air in the chamber 99 will be through the pipe |32.

After holes have been drilled in a coal face the cuttings may be cleaned out by means of the nozzle |33 connected to the outer end. of a flexible hose l which communicates with the compressed air supply pipe 3l. The flow of the compressed air from the pipe 3l' through the nozzle |33 may be controlled by the valve |31 actuated by the lever V3i. After the drill holes have been cleaned and the blasting charges inserted the spaces in front of the blasting charges may be lled as above explained with the granular material and uniform tamping thereof se- `cured so as tof more effectively pre-determine the action of the blasting down of the coal to secure the maximum amount of lump coal and a minimum amount of slack in accordance with the hardness of the coal and the amount of blasting material used in the particular system of arrangement of drill holes being employed.

In order to cushion the action of the blasting charge an air space may be provided between the blasting charge and the charge of tamping material, by inserting into the drill hole a tube of pasteboard paper closed at both ends, after the blasting charge has been inserted.

During transportion of the machine shown in Figs. l and 2 to and from the places where thel blasting operations are to be carried on the flexible sections |35 and l2@ of the hose for the nozzles 25 an-d |33 may be supported on the horizontal plate |35 at the forward end of the machine while the operator may stand on the supporting platform |39 at the rear end of the machine in position to control the clutch I9 while the reel 26 is being rotated to permit paying out of the electric cable 2l which is connected to a distant source of electric supply for the electric motor i3. The operator while standing on the platform 85 may also operate the controller for the electric motor i3 and the brake lever 9. When the machine reaches the place in the mine where blasting operations are to be carried on the forward extension of the truck frame beyond the forward axle 32 will permit the forward end of the machine to be located as close to the working face of the coal vein as the mine track 8 will permit and therefore relatively short lengths of flexible hose |24, |34 for the nozzles |25 and |33 will be sufficient.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and We wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of our invention, what we desire to secure by Letters Patent of the United States is:

1. Apparatus for tamping drill holes in a mine face comprising the combination with a portable supporting frame, of a source of compressed air mounted thereon, a hopper for tamping material mounted on said frame, means at the bottom of said hopper and within the hopper to afford a mixing chamber, a valve for controlling the flow of tamping material from said hopper into said mixing chamber, a multiple nozzle at the bottom of said hopper and surrounding said valve for aerating the tamping material to facilitate its iiow into said mixing chamber, means for controlling such aeration, land means for directing the flow of a mixture of air and tamping material from said mixing chamber into a hole to be tamped.

2. Apparatus for tamping drill holes in a mine face comprising the combination with a truck, of a source of compressed air thereon, a car body hopper on the truck, mechanism affording a mixing chamber at the bottom of said hopper and enclosed by the hopper, a valve for controlling an opening in the top of said mixing chamber, means comprising an air nozzle for aerating the tamping material adjacent to said opening to facilitate the fiow of tamping ma.- terial from said hopper through said opening into said mixing chamber, said valve when closed being adapted to confine air under pressure in said chamber, and means for directing the flow of compressed air from said chamber to effect flow of tamping material from said chamber to the hole to be tamped.

3. Apparatus for tamping drill holes comprising the combination with a hopper for dry granular tamping material, of a housing within the hopper defining a mixing chamber and provided with a passageway communicating with the interior of the hopper to enable material to pass from the hopper into the mixing chamber, means for aerating the said material to facilitate its flow into the mixing chamber, and mechanism for controlling the passage of the material through the passageway from the hopper into the mixing chamber.

4. Apparatus for tamping drill holes comprising the combination with a source of fluid pressure, of a hopper for dry granular tamping material, a housing within the hopper defining a mixing chamber and provided with a passageway communicating with the interior of 'the hopper, means comprising apertured pipes leading from the source of uid pressure into the hopper for aerating the material in the hopper to facilitate its flow into the hopper, the aperatures in the said pipes being directed upwardly and angularly toward the said passageway, and'mechanism for controlling the passage of material through the will be closed. The pressure of the air conned in the chamber 12 will then diminish by leakage past the piston 1| which lits loosely in the cylinder 10. Consequently the pressure between the disks 49 and 50 of the friction clutch will be lessened to allow the disks to slip and the compressor shaft I1 to stop, preventing any further operation of the air compressor.

By permitting the valve 95 to remain open the operation of the air compressor including its starting and stopping will be entirely automatic so long as the electric motor I6 is operating.

Whenever the air pressure in. the tank 38 fallsso low that the friction clutch 49, 50 cannot be applied with sumcient pressure, starting operations may be effected manually by means of the lever 89 which is pivoted at 90 and is provided with a pressure arm 9| in position to engage a cross-piece 92 of the operating lever 60. By starting the motor I3 and manually applying the friction clutch 49, 50 the air compressor |6 may be operated to supply pressure to the tank 38 while the valve lever 44 occupies its horizontal position shown in Fig. 2 with the passage-ways of the valve 43 in the positions shown in Fig. 2a. After sufficient pressure has been built up in the tank 38 the valve 8| will be automatically operated as above explained. It should be understood that the aircompressor I6 is connected to the tank 38 through the pipes 80, 31 and controlled by valve 43. The pressure in the tank 38 may be predetermined by the setting ofthe relief valve 96 in accordance with the reading on the pressure gauge 42 as shown in Fig. 2.

On the truck frame 6 between the air compresser I6 and the pressure tank 38 is mounted al large hopper 98 for containing the granular material such as stone dust or sand which is to serve as the tamping material. At the bottom of the hopper 98 is an auxiliary circular chamber 99 formed by the hollow dome-shaped housing forming the partition |00 which has a circular opening |0| in its upper side to receive the valve |02. The bottom of the chamber 99 is the upper flat horizontal surface |03 of the upper side of the circular plate |04 which is secured rigidly to the dome-shaped-housing |00.

The dome-shaped housing forming the partition |00 is provided with an annular flange |05 which is secured by means of cap screws |09 to the hopper floor plate I 01 which is secured rigidly to the lateral longitudinal walls of the hopper 93. It will thus be seen that no communication is established between the hopper 98 and the auxiliary chamber 99 except through the opening |0| in the upper side of the dome |00 and this opening is controlled by the valve |02. A vertical rod |03 is rigidly connected at its lower end to the valve |02 and the upper end of the rod |08 is pivotally connected at |09 to the lever I I0 shown in Figs. 1 and 3. The lever I I0 is fixed at to the rockshaft ||2 which is journaled at its ends in the opposite side walls of the hopper 98. One end of the rockshaft ||2 is provided with an actuating lever ||3 as shown in Figs. 1 and 2.

The lever arm ||0 extends under the upper crosspiece ||4 which is connected between theupper edges o-f the opposite side walls of the hopper 98. The crosspiece I I4 serves as an abutment to prevent opening of the valve |02 by movement upwardly from the dome |00. By depressing the lever H3 the valve |02 may be opened by downward movement to its position i1- lustrated in dotted lines at` |02' in Fig. 3. The

tamping material may then flow from the hopper 98 into the auxiliary chamber 99 to fill the latter. To facilitate the flow of the tamping material from the hopper 98 into the auxiliary chamber 99 a pipe ||5 connects the pressure supply pipe 31 to the circular perforated pipe H0. By referring to`Fig, 3 it will be seen that the perforations ||1 in the circular pipe ||6 are directed upwardly and angularly toward the valve opening |0| in the top of the housing |00. When the valve |02 is depressed to establish communicag tion between the hopper 98 and the auxiliary chamber 99 the valve I|8 may be opened by the lever ||9 as shown in Figs. 1 and 2. The air under pressure will then flow from the tank 38 through the perforations ||1 to aerate the tamping material, evaporate excessive moisture therefrom so as to loosen the granules and mix them to facilitate their flow through the opening |0| into the chamber 99.

After the chamber 99 has been lled with the granular tamping material the valve |02 is again closed by lifting the lever ||3 back to its initial position. The valve |02 preferably comprises an annular exible element of leather, rubber or other exible material which is held against a conical annular seat in the cone-shaped support 2| bymeans of the circular plate |22 and the lower screw threaded end |23 at the bottom of the rod |08.

The granular material that flows into the chamber 99 is forced by air pressure through the pipe |24 and the nozzle |25 for flow into the drill holes. The branch pipe I 26 is connected between the air pressure supply pipe 31 and the annular chamber |21 which surrounds the depending annular skirt |28 as shown in Fig. 3. The lower edge of the annular skirt |28 is spaced above the horizontal surface |03 of the bottom plate |04. The housing |00, the skirt I 28 and the peripheral support |29 together with the annular flange |05 may be in one integral casting and the support 29 is so shaped as to make an air tight fit with the bottom plate |04. l

The ow of the compressed air from the pipe 31 through the pipe |26 into the annular chamber |21 may be controlled by the Valve |30 which is actuated by the lever |3|. A pipe |32 leads from the interior of the chamber 99 into the flexible hose |24.`

It will thus be seen that by affording the relatively small auxiliary chamber 99 and closing the same by means of the valve |02 after the granular tamping material has filled this chamber a pre-determined pressure may be relied on to afford a uniform tamping of the granular material in the various drill holes into which it is directed by the opening of the valve |30 while the nozzle is inserted into the drill holes. When the valve is open, compressed air has free flow around the annular air space |21 and thence radially under the circular edge of the annular skirt |28. It should be understood that by reason of the angle of repose of the granular material in the chamber 99 such granular material will not fill the annular space |21. The annular distribution of the compressed air radiallyrand inwardly under the edge of the skirt |23 will effect suiicient aeration of the granular material to produce a mixture of air and granular material to effect free flow of the latter outwardly from the 'chamber 99 through the pipes |32 and flexible hose |24 and thence through the nozzle |25. The nozzleV |25 may always be open because as soon as the valve |30 is closed the ow through the hose |24 will discontinue althoughV still filled with the mixture of air and granular material. The auxiliary chamber 99 may be of suicient capacity to afford operations to tamp a plurality of drill holes before it is necessary to re-open the valve |82 to re-iill the chamber 99.

The diameter of the nozzle |25 should be relatively smaller than the diameter of the drill hole so as to fit loosely in the latter and provide for escape of air from the drill hole during the tamping operation. Due to the expansion of the air while travelling through the hose and the nozzle the tamping material receives its acceleration and final velocity, when emerging from the nozzle. The greater the final velocity7 of the tamping material the more effective will be the tamping action. Therefore, sufficient clearance between the outer surface of the noz- Zle and the drill hole should be allowed to permit f-ree escape of the air while the tamping material is lodged at the inner end of the drill hole.

As above explained this tamping operation may be regulated by having the pressure in the tank 38 uniform and confining the granular material in the chamber Q9 by the closure of the valve m2. When the air pressure is exerted in the chamber 99 the flexible element |20 tends to expand radially to hold the opening l! tightly closed. Therefore the only escape for the compressed air in the chamber 99 will be through the pipe |32.

After holes have been drilled in a coal face the cuttings may be cleaned out by means of the nozzle |33 connected to the outer end of a flexible hose |34 which communicates with the compressed air supply pipe 3l. The ow of the compressed air from the pipe 3l through the nozzle |35 may be controlled by the valve |37 actuated by the lever IST. After the drill holes have been cleaned and the blasting charges inserted the spaces in front of the blasting charges may be filled as above explained with the granular material and uniform tamping thereof secured so as to more effectively pre-determine' the action of the blasting down of the coal to secure the maximum amount of lump coal and a minimum amount of slack in accordance with the hardness of the coal and the amount of blasting material used in the particular system of arrangement of drill holes being employed.

In order to cushion the action of the blasting charge an air space may be provided between the blasting charge and the charge of tamping material, by inserting into the drill hole a tube of pasteboard paper closed at both ends, after the blasting charge has been inserted.

During transportion of the machine shown in Figs. 1 and 2 to and from the places where the blasting operations are tobe carried on the ilexible sections |34 and IZQ of the hose for the nozzles and |33 may be supported onv the horizontal plate |35 at the forward end of the machine while the operator may stand on the supporting platform i3@ at the rear end of the machine in position to control the clutch I9 while the reel 26 is being rotated to permit paying out of the electric cable 2l which is connected to a distant source of electric supply for the electric motor i3. The operator while standing on the platform |36 may also operate the controller for the electric motor |3 and the brake lever 9. When the machine reaches the place in the mine where blasting operations are to be carried on the forward extension of the truck frame beyond the forward axle 32 will permit the forward end of the machine to be located as close to the working face of the coal vein as the mine track 8 will permit and therefore relatively short lengths of flexible hose |24, |34 for the nozzles |25 and |33 will be sufficient.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and we wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of our invention, what we desire to secure by Letters Patent of the United States is:

1. Apparatus for tamping drill holes in a mine face comprising the combination with a portable supporting frame, of a source of compressed air mounted thereon, a hopper for tamping material mounted on said frame, means at the bottom of said hopper and within the hopper to afford a mixing chamber, a valve for controlling the flow of tamping material from said hopper into said mixing chamber, a multiple nozzle at the bottom of said hopper and surrounding said valve for aerating `the tamping material to facilitate its flow into said mixing chamber, means for controlling such aeration, and means for directing the flow of a mixture of air and tamping material from said mixing chamber into a hole to be tamped.

2. Apparatus for tamping drill holes in a mine face comprising the combination with a truck, of a source ofl compressed air thereon, a car body hopper on the truck, mechanism affording a mixing chamber at the bottom of said hopper and enclosed by the hopper, a valve for con. trolling an opening in the top of said mixing chamber, means comprising an air nozzle for aerating the tamping material adjacent to said opening to facilitate the liow of tamping material from said hopper through said opening into said mixing chamber, said valve when closed being adapted toconfine air under pressure in said chamber, and means for directing the ow of compressed air from said chamber to effect flow of tamping material from said chamber to the hole to be tamped.

3. Apparatus for tamping drill holes comprising the combination with a hopper for dry granular tamping material, of a housing within the hopper defining a mixing chamber and provided with a passageway communicating with the interio-r of the hopper to enable material to pass from the hopper into the mixing chamber, means for aerating the said material to facilitate its flow into the mixing chamber, and mechanism for controlling the passage of the -material through the passageway from the hopper into the mixing chamber.

. 4. Apparatus for tamping drill holes comprising the combination with a source of fluid pressure, of a hopper for dry granular tamping material, a housing within the hopper defining a mixing chamber and provided with a passageway communicating with the interior of the hopper, means comprising apertured pipes leading from the source of fluid pressure into the hopper for aerating the material in the hopper to facilitate its flow into the hopper, the aperatures in the said pipes being directed upwardly and angularly toward the said passageway, and mechanism for controlling the passage of material through the passageway from the hopper into the mixing chamber.

5. Apparatus for tamping drill holes comprising the combination with a source of fluid pressure, of a hopper for dry granular tamping material, a housing within the hopper defining a mixing chamber and provided with a passageway communicating with the interior of the hopper to enable material to pass from the hopper into the mixing chamber, means for aerating the said material to facilitate its flow into the mixing chamber, a valve for controlling the passageway including a flexible sealing member operable under iiuid pressure in the mixing chamber to form a fluid-tight closure for the passageway and to maintain a constant fluid pressure in the said mixing chamber.

6. Apparatus for tamping drill holes comprising the combination with a source of fluid pressure, of .a hopper for dry granular tamping material, a housing within the hopper defining a mixing chamber and provided with a circular port communicating with the interior of the hopper to enable material to pass from the hopper into the vmixing chamber, a valve for controlling the port including a conical support, a conical annular seat in the support, an annular flexible sealing.

member, and means for holding the flexible sealing member against the seat, the flexible sealing member being expansible under fluid pressure in the mixing chamber to form a fluid-tight c10- sure for the port and to maintain a constant fluid pressure in the mixing chamber.

7. In a track mounted tamping apparatus, the combination with `a truck, of a source of fluid pressure thereon, a hopper for dry granular tamping material a housing Within the hopper dening a mixing chamber and provided with a passageway communicating with the interior of the hopper to enable material to pass from the hopper into the mixing chamber, a valve for controlling the passageway including a support, a seat in the support, la flexible sealing member, and means for holding the flexible sealing member against the seat, the flexible sealing member being expansible under fluid pressure in the mixing chamber to form a fluid-tight closure for the passageway and to mantain a constant uid pressure in the mixing chamber.

8. Apparatus for tamping drill holes comprising the combination with a source of fluid pressure, of a bell-shaped housing for dry granular tamping material dening a mixing chamber and provided with an interior depending skirt carried by said housing and terminating short of the bottom wall thereof, and communicating means connecting said source of fluid pressure to said housing at a position adjacent said skirt.

9. Apparatus of the class described, comprising a fluid tight bell-shaped housing defining a mixing chamber for a fluid and a granular material, said chamber being provided with an interior depending skirt carried by said housing terminating short of the bottom wall thereof and dening a circumferential port for the reception of fluid, means for admitting fluid to said port, means for admitting granular material to said chamber, and means to deliver the mixed fluid and granular material from said chamber.

l0. In track mounted apparatus for charging a drill hole in a mine face with tamping material, the combination with a truck adapted to travel on a mine track, of an air compressor on the truck, astorage tank forcompressed .airconnected to said air compressor, a container of relatively large dimensions mounted on said truck and adapted to store dry granular tamping material, means affording a closed mixing chamber in the bottom of said container of relatively small dimensions,

a Valve for admitting tamping material into said chamber from said container and for closing said chamber to said container, said chamber being 85 provided with an interior skirt depending from the side walls thereof and terminating short of the bottom Wall thereof, thereby defining a circumferential port for the reception of air, means affording communication between said storage tank and said port whereby said air and tamping material are mixed in said chamber, and a hose leading from said chamber and adapted to communicate with a drill hole in the mine face.

NILS D. LEVIN. ERNST F. MUILER. 

